Sheet feed



June 2, 1942. F. NIGRA ETAL 4 SHEET FEED Filed Aug. 2, 1e4o 2 Sheets-Sheet 1 lllllv amnjm INVENTOR FERDINAND N/GRH mvo' BY 1 Max 7 A T??? Y June 2, 1942. F. NIGRA ETAL 2,235,224 I 'SHEET FEED v Filed Aug. 2, 1940 2 ShQeets-Shget 2 9 IN VENZOR FERDINAND Nrcfia mm Max E. Toav' 7 AT ORNE Patented Juhc Z1942,

s- PATENT OFFICE:

- in which, v

Figure 1 is a fragmentary side elevation of a fed thereto.

" UNITED STATE shear .FEED' Ferdinand mm and Max. a; Toby, San

cisco, Calif... assignora to Niagara Duplicator 00., San Francisco, Calif.

Application August 2, 1940, Serial No. 349,150,

9, Claims. (91. 211-42) v cable, the device is particularly shown as applied The invention relates toa device for effecting the primary advancement of a sheet of paper or the like from a stack of the sheets to a mechanism which is to operate upon the sheet.-

, An object of the-invention is to provide a sheetfeeding device of the character described which is particularly adapted for use with a rotary duplicator of the character-of that described in U. S.

'Patent No. 2,089,979 of August 17, 1937.

Another object is to provide an improved. sheetfeeding device which is structurally independent of a tray providing a stack'of sheets to be printed,

as that disclosed in .the aforesaid patent.

. A further object is to provide a sheet-feeding and may be actuated by a drive mechanism such device which applies a drag shoe in such a manner that the initial pressure of engagement of the shoe with the sheet to be moved exceeds the working pressure .of the shoe during the movement of thesheet, said working pressure being constant. 1 a

.An added o'biect is to provide -a particularly simple and pos tive control for the shoe during its return 's troke, during which it is free from the sheets on the supply stack.

The invention possesses other objects'and features of advantage, some of which, with-the foregoing, will be set forth or be apparent in the following description of a typical embodiment of the invention, and in the accompanying drawings,

duplicator having the primary sheet feed of my invention operativelyassoclated therewith.

Figure 2 is an enlarged fragmentary section taken at the line22' in Figure 1. v Figure 3 is an enlarged elevation of a dogging device of Figure 1.

to the structure of the duplicating machine disclosed in said patent, No. 2,089,979, whereof the printing element comprises a stencil sheet. The printing cylinder 2 is supported on a shaft I2 for rotation on and between side frame members Ill and II which extend upwardly and in mutual opposition from a rectangular base frame 12 and receive the duplicator-mechanism between them, and suitable means (not shown) are provided for. rotating the cylinder for effecting printing cycles thereof. 1 r

Referring particularly to the somewhat dla-' grammatic showing of Figure 5, a sheet. I of print-receiving material which has been moved from a feed table or tray II by the operation of the present device to position its front end portion between pairs of upper, and lower rollers 16 and I! may .be thereafter engaged by and between Figure 4 is a perspective view of the feed mechanism and a tray from which sheets areto'be Figure 5 is-';a sectional and somewhat diagrammatic elevation of the mechanism, the

parts being related as at the end 'of a working stroke of the drag shoe. 1

Figures 6 and I are elevations of the mechanism at the ends of the second and third'cyclic move .ments ofthe shoe.

As shown, the present sheet feed hasbeen adapted for successively supplying sheets I of said rollers to advance it for the disposal of its front end portion between the printing element 'on the rotary cylinder 8 and theimpression roller 9, and is finally gripped between the cylinder and the impression roller to continue the feeding movement of the sheet while the latter is being printed;

The impressiqnroller 9 is mounted for its free rotation on a shaft I! which is carried by and between corresponding and forward ends of leverlike members 20' which are intermediately pivoted V on a fixedly disposed rock-shaft z I, said shaft be- I! out of engagement with the cylinder.

The rollers are mounted on a shaft 22 which is" loosely journalled in and between the upper ends of lever-like members 29 which are disposed in generally upright position and are intermedipaper or the. like to -a duplicating machine hav-v ing a stencil or printing matrix carried on a rotary cylinder II for the printing engagement of the advance sheet betweensthe printing element and ately pivoted on the shaft 2| for rocking independently ofthe latter shaft. Preferably, and as shown, the upper lever portions are curved rearwardly to dispose the shaft 28 directly above the line of lower feed rollers II for the cooperation of complementary pairs of feed rollers to grip a sheet I between them.- The lower arms ofthe levers 20 are connected to the side frame members an impression roller 9. While otherwise appli- 5 I. a II y m ns of tension 8nr1ns8 3l opera- I tive in the planes of movement of the levers whereby the levers are yieldingly urged to maintain their engagement with adjustable stops 32 which are providedon the frame members and while the rollers I6 are in'a limiting lowered position with respect to the axis of the rollers IT.

A fixedly disposed shaft 33 carries the rollers i1, and said rollers are segmental whereby their cylindrical face portions extend through an are which is somewhat less thana full circle. The rollers have like p'erimeters and are similarly positioned on the shaft 33 whereby they may simultaneously coact in like manner with the rollers it above them. As the rollers I! are rotated, their cylindrical faces are arranged to engage and grip a sheet 1 between them and the rollers l6 at a line at or adjacent the common plane of the shafts 28 and 33,-it being noted that the rollers ll coact with the rollers i5 only for 7 the part of a rotative cycle thereof during which their. cylindrical faces are in opposition to the latter rollers. Preferably, and-as shown, the

circles of the cylindrical faces of the rollers are arranged to intersect the circles of the depressed rollers IS whereby the latter rollers may be pressed upwardly against the resistance of the springs 3i, and an equalized and resilient gripping of the sheet 4 between the sets of rollers i6 and H is thus assured while the rollers are coactive in the described manner.

A plate member 34is fixedly mounted in and between the frame members) I0 and Win generally horizontal disposition and in a plane slightly below the rollers i6 for the feeding movement of a sheet I thereover, and rectangular openings are provided in the plate oppositeline of stops 35 against which the advance edge of a sheet I is arranged to abut when the sheet is initially advanced from the feed table l8. Forwardly of the .line of-stops 35, the plate 34 slopes upwardly in generally tangential relation to the cylindric face. The rear portion of the plate 34 extends downwardly to a support element of the frame.

Means are provided for liftinga front sheet edge out of engagement with the ,line of stops- 35 at the proper time in a cycle of operations of the cylinder 3 whereby the sheet I may'then be advanced by the rollers l6 and H. In the present structure, fiat fingers 36 are hingedly mounted on a fixed cross-member of the frame below the plate for swinging into and through the various plate openings opposite the stops 35. The fingers 36 overlie the shaft 33 and each is provided with a depending projection which i arranged to constantly and similarly ride on r the top of the shaft; said shaft being cylindrical thereat except for a segmental notch provided therein. when the finger projections engage the bottoms of the underlying shaft notches, the fingers 36 are arranged to be disposed in the plate openings in coplanar relation therewith, whereby they may then provide a portion of the support surface for a sheet I as it is moved against the stops 35. When the finger projections ride on the cylindrical part of the en ged shaft surface, the fingers are raised to sheet clear of the stops 35 to thereafter permit a further advance of the sheet for its printing. Spring-pressed fingers 38 resiliently engage the tops of-the lifting fingers 36 or with a sheet I which is disposed over the latter fingers. The fingers 38 insure a directing of the sheet l to an initial engagement with the stops 35 as the sheet is inserted between the then spaced rollers i6 .and I1, no parts of the cam-like rollers ll protruding above the plate 3 5 during the latter process.

It will now be noted that the positioning of a sheet l against the stops 35 is arranged to be efiected by the operation of a drag shoe 39 against the top sheet 1 of a supply stack of sheets. The shoe 39 is actuated from the cylinder drive means in such synchronism with the operation of the shaft 33 as to move the top sheet I forwardly from the stack to eiiect a buckling engagement of the engaged sheet I against the stops 35 as the first operative step with respect to "he printing of a sheet,-and the present invention particularly concerns the control of the shoe 35 in the desired manner and sequence by the duplicator actuating mechanism.

The required operations of the shafts 2| and 33 and of the shoe 33 are primarily derived from the controlled reciprocative movement of a bar .4| which pivotally engages an arm 32 extending rigidly from the shaft 2| and is forked at its upper end to span a hub to extending from an end of the cylinder 8. The bar 5| is disposed in generally upright position in parallel relation to the frame side I0, and a plate cam 43 is fixedly mounted on the cylinder hub adjacent and inwardly of the forked portion of the bar 4|. At its inner-side, and in the plane of the cam 43, the bar 4| carries a'roller 44 for periodic engagement by the cam to lower the bar and so oscillatethe shaft 2| as is required for controlling the disposal of the impression roller 9. It will be noted thatthe spring 26 for the shaft 2| is operativeto urge the upward disposal of the arm 42 and the bar 4|.

48. A roller 49 is mounted at the outer face of the bar 4| and constantly engages in the slot 48 whereby the element 45 is arranged for oscillation about its pivotal axis as the'bar 4| is reciprocated, said axis being fixed. The segmental gear 46 is utilized to eflect the periodic I rotation of the shaft 33 which carries the segmental feed rollers through the operation of lift the front edge portion. of the positioned a pinion 5| which it constantly engages and which is connected with the shaft 33 through a suitable one-way clutch 52 in such a manner that the shaft 33 is rotated only by and during a return movement of the element 45 to its normal position which is shownin Figure 1. It will be understood that it is this rotation of the shaft 33 which periodically effects the described operative rotation of the segmental rollers H at the appropriate time in each rotative cycle of the printing cylinder 8.

An arm 53 overlies the cylinder hub", is pivoted to the frame member H) at its forward end, and carries a roller 55 which is arranged to constantly and gravitationally rest on the periphery of a plate cam 54 which is mounted on the hub beside the cam 43. A link 56 extends from the free end of the arm 53, and a link 5! extends from the arm "of theactuator member II; the links 56 and I! are utilized for cyclically controlling the positioning of thedrag shoe "in" a manner to be hereinafter described. a

It will now be noted that the drag shoe 3! is carried at the rear'end of an arm I, and com- .prises a pair ofaxially aligned and spaced segmental elements providing friction faces of rubber or the like and non-rotatably mounted on the arm forengaging a sheet I. The other end of the arm 58 is fixed on a bar 6| extending horizontally and across the forward end of the tray space. As shown, the bar 6| is intermediately slotted longit dinally thereof, [and a thumb screw 62 extends from the forward arm end and through the slot of the bar ll for clamping the arm to the bar in adjusted position therealong; this adjusted mounting of the shoe on the bar 6| provides for a centering of the shoe over the sheets on the feed table II.

A rock shaft 63 is suitably journalled in and between bearings provided on the frame members I. and II below the level of the bar ii, and is provided with arms 64 fixedthereto'and extending upwardly to pivotal connections with the bar 6| which is parallel to the shaft. As particularly shown, the bar Si is provided with pressure caused by the swinging of the shoe-carrying bar fl about its axis of pivoting at the pins I by the link I! acting through the pin 33 of the arm I! in the slot 14 of the bar extension 66. Under static conditions at the start of' a work'- ing stroke, the pull on the link 51 first creates a shoe, pressure which increases until a forward dragging component thereof. sets the paper in motion with the accompanying forward swinging of the arm 64 against resistance of the spring 09. As soon as the motion of the freed top sheet begins, the part of thestarting pressure caused by the pull of the link it is immediately lessened. As the shoe is swinging forwardly on the arms .4, the pin I3 moves upwardly in the slot 14 whereby the effective lever arm for rocking is down-turned terminal extensions cream 65 and it which receive the upper ends of the arm 64 between them and are pivoted to said arm ends at pivot pins 61. .An arm 68 extends rigidly from the shaft 63, and a spring 69 is constantly coactivebetween the arm 68 and an anchorage Ii on the frame member H to yieldingly urge a rearwardly swung positioning of the rock frame provided by the assembly of the shaft 61 and arms 64.

An arm I2 is pivotally mounted on the shaft II adjacent a fixed arm 64 of the shaft, and the free end of the arm 12 is provided with a pin or roller 13 extending parallel with said shaft and closed rearwardly offset relation of slot. ll to a 1 plane parallel to it and including the pivotal axis of the bar 6|. I

engaging in a slot 14' provided in the extension 1 it below its pivot pin 61 and extending generally radially of 'said pin, it beingno'ted that the extension-5e is L-shaped in elevation and provides a rearwardly extending arm portion 15 below its slot II. The link 51 from the actuator arm 41 is pivotally connected to the arm I! at an intermediate point thereof whereby longitu dinal reciprocations of the link 51 are arranged to operate through the pin I3 and the extension 86 to oscillate the rock frame of the shaft 63 and arms 64 for effecting working and return strokes of the shoe 3!, it being noted that the bearing of the shoe on the top sheet of the paper on the feed table II will limit the rocking of the bar 6| about its pivotal axis on the" arms 6, provided thev bar is free to rock on the arms,- The latter condition is arranged to obtain'when a forward, and working,stroke of theshoe is being effected by reason of a rocking of the actuator element 45 from its position of Figure-1 to its position 01' Figure 4.

It will be noted that the present swinging mounting of the dragv shoe 39 on the arms M and its actuation-by the link 51 through the engagement of the pin 'll'in slot of the bar extension 66 is such thata working movement of the shoe resting on the top sheet 1 provides a constant pressure engagement of the shoe which is slightly less than the static'pressure which obtains at the start of the working stroke of the shoe. This pressure relation results from the fact that during a working stroke of the drag shoe 3!, the shoe is pressed against the top sheet lessened, with the result that the portion of the shoe pressure produced by the swinging of the manner and for the same length of stroke over the stack regardless of the depth of the "stack of sheets in the tray, this by reason of the dis- When the engaged sheet l'has been advanced against the .stops 35 to slightly buckle the sheet between the stops and shoe inthe manner in- .dicated in Figure 4, the forward shoe motion ceases and the shoe is raised to permit a rearward flattening out of the advanced sheet while "its front edge is lightly held between the fingers 3i and II, this insuringw. proper positioning of the paper for its subsequent forward feeding for its printing. The said lifting of the shoe to release the paper is arranged to be effected by rocking the bar 6| about its pivotal axis on the rock frame arms il-while said arms are disposed forwardly at the stroke of the shoe.

' As shown, the free end of the arm I5 carries a roller I6, and a cam arm TI is provided in the plane of movement of the roller I6 for engagement beneath the roller to rock the arm 15 and bar 6! for swinging the shoe upwardly from the sheet.- The cam arm II is, shown as being pivoted to theframe meinber II at a point forwardly of the shaft v63, is intermediatelyconnected by the link 56 to thevarm i3, and has its upper edge providing a cam face .18 for such lifting engagement of the roller 16 of the arm 15 as to effect and maintain an inoperative positioning of the shoe 39 at the end of a working stroke and during a return stroke thereof. The portion of the cam face 18 which is engaged beneath the roller Ii when the cam arm "I1 is fully raised is straight,

- and is then so disposed that'the return path of the raised shoe is substantially parallel to the tray bottom. The plate cam 54 which controls the arm ll through the arm 53 and link 56 has a profile comprising arcuate portions of different radius connected by tangents and of such relative lengths that the arm 11 is respectively raised and lowered at the ends of the working and return strokes of the shoe II.

of the sta ck of sheets by a total force including 1 both thatof the spring '8 and the additional end of the working Means are provided for insuring a freeing of the topsheet 1 of a stack of sheets on the table |8 as the sheet is; individually advanced by the action of the shoe-38 upon it. 'As particularly shown inFigures 1 to 3, complementary side wall members 8| are mounted on the table top 82 for receiving a stack of sheets 1 between them in the tray space thus defined. The members 8| are relatively adjustable to and from each other, have mutually intumed bottom flanges 83, and are provided with mutually opposite and upright slots 84. The slots 84 serve as guideways for weight members 85 secured for sliding vertically along, the outer plate sides by means of headed extensions 86 slidably fitting-the slots. The head portion 8l-of each weight extension 88 is formed to provide an acute-angled edge 88 extending obliquely downwardly to the plane of the inner wall face whereby said edge may overlie a stack of sheets in the tray when the stack is closely fitted between the walls 8 The tray bottom 82 is formed with an upward and forwardly inclined offset portion 89 adjacent its forward end, said end registering with the rear end of the horizontal portion of the plate '34 of the duplicator mechanism and the offset 88 providing a positioning stop' for a stack of sheets in the tray. Particularly when a stack of sheets in the tray has been reduced to but a few sheets and is relatively flexible, the stack may tend to'slide forwardly over the stop 88 under the influence of a working stroke of the drag shoe upon it; to prevent such a displacement of the reduced stack, the tray bottom 82 is preferably roughened, at least beneath the zone of action of the shoe, to insure a holding frictional engagement thereof with the bottom sheet of the stack; a thin surfacing coating 98 of carborundrum or the like is preferred.

When a stack of sheets I is first placed on the table l8 with its front end in contact with the positioning stop provided by the oii'set 88, the weight members 85 are inoperatively disposed and the walls are adjusted laterally of the table top 82 to fittedly receive the stack between them. The weight members 85 are then lowered in the respective slots 84 torest their heads'8'l upon the stack sides whereby their edges 88 obliquely engage along the edges of the top sheets of the stack to wedgedly urge the engaged sheet edges inwardly of the stack side planes and so slightly lift at least the top sheet by buckling it to admit air beneath it adjacent the contact points; in this rotation of the cylinder 8 operates to raise the arm 58 and so lift the cam arm 11 to rock the bar 4| to fully lift the shoe with respect to the sheet, it being recalled that the first lifting of the shoe releases the sheet to flatten out rearwardly. The return stroke of the actuator 45 not only raises the sheet from the stops 35 and promanner, cohesive and air-pressure binding of the top sheet with the underlying sheet is broken, and resistance to-the forward movement of the sheet by the shoe 88 is minimized while the remainder of the sheets are held in place by the edges 88. 7

Assuming that the cylinder 8 is continuously rotating and that each cycle of operationsof the shoe 88 begins with the shoe disposed in its limiting rear position while resiliently bearing against the top sheet of a stack of sheets in the tray, as shown in Figure 1, the first cyclic step comprises the forward movement of the shoe to dispose and slightly buckle'the top sheet 1 against the line of stops 85 of the plate 84. This step is the shaft 88 of the segmental feed roller nor the arm 58 is affected during this movement of the actuator.

pels it forwardly by action of the rolls I6 and H, but also swings the arm 12 rearwardly to efiect a return movement of the shoe 38 to its position of Figure 6 while the shoe-is held in raised position by the action of the cam 54. After the drag shoe reaches its limiting rear position, the continued rotation of the cam 54 lowers the arm 11 to permit the shoe to resiliently bear upon the new top sheet in the stack for the repetition of the cycle; the actuator 45 is inactive during this step.

Means are provided for rendering the entire sheet feeding mechanism inoperative whileleaving the cylinder rotatable as for the placement or removal of a stencil with respect to it, said means comprising a pawl or dog member 8| which is operative against the actuator member 45 when the bar 4| is in its lowest position to secure the member against a return swinging to its normal position and so eliminate working and return strokes of the shoe 38 and rotation of the shaft 33. As particularly shown in Figure 5, the dog 8| is intermediately pivoted to the frame member I0 so that it may extend generally tangentially of the circle of movement of the tip of the actuator arm 41 to dispose its tooth 82 slightly within said circle. A notch 94 is' provided across the extremity of the arm 41 for receiving the dog tooth 82; when the dog is free to act, the outer end of the arm 41 is arranged to displace the dog to pass under it as the member 45 approaches the limit of the stroke caused by the lowering of the bar 4| and so operatively engage the pawl tooth in the notch 94 to permit a very slight return movement of the actuator which does not affect the shaft 83 or the shoe positioning.

When the described primary sheet feed isto be used, the dog 8| is held out of arm-engaging position by a suitable means. As particularly shown, a bell crank lever 85 is pivoted .on the plate l8 above the pivotal point of the dog 9| and has one arm 88 thereof operative as a cam against and along the top of, the dog and its other arm 81 providing a setting handle for the camarm. The arrangement is such that the lever,

' derstood that the line of pressure of the dog 8| Having the parts as in Figure 4, the continued 5 againstthe cam arm 88 of the lever 95 is eccen- -tric to the pivotal axis of the lever whereby the lever is releasably held in its operative position.

When the arm 88 isswung to dispose the contact point 88 at the same side of the common plane of the pawl and lever axes, the dog is freed to function as a locking means for the actuator by engagement of its tooth in the notch 84 of the arm 41 when the latter starts a return stroke.

Recalling that the spring 88 constantly urges a rearward swinging of the rock frame which carries the shoe 88, and that the actuator element 45 would usually be free of the bar 4| which disposed it for the voperatic engagement of the dog 8| with it, a release setting of the lever 85 must actually eifect a freeing of the element only at of the cam arm 96 comprises the outer extremity of a spring pressed. member. which,extends.in and from a radial socket in the arm 98 for a limited degree of protrusion therefrom, and the dog tooth 92 so engages the notch 94 that the urge to a return stroke of the element under the influence of the spring 26 retains the dog in the notch against-the yielding urge of the member 99 to free the dogas it moves to its limiting release .position in which it urges a rocking of the dog to dispose its point out of the path of travel of the actuator arm 49. Having the dog 9| opera- I tively engaging the actuator 45, an inoperative disposal of the dog may be effected by the spring pressed member 99 only as the downward movement of the bar ll is completed to rock the actu ator to free the dog tooth from the notch and so permit the member 89 to act to swingthe dog to an inoperative position in which it is held while the feeding mechanism is in use. In this manner, the sheet-feeding mechanism may operate only in synchronism with the cylinder.

From the foregoing description taken in conv i 4. A structure in accordance with claim 3 whereof thexlast means is operative directly upon and throughthe support member in synchronism with therocking of the frame by the frameoscillating means. I

5'. In a paper feed, a fixedly disposed table I for supporting a supply stack of sheets in fixed 6. In a paper feed, a fixedly disposed table ,for supporting a supply stack of sheets in fixed nection with the accompanying drawings, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains. While we have described the features and the principle of operation of a structure which we now consider to be a preferred embodiment of our invention, we desire to have it understood that the showing is primarily illustrative, and that such changes may be made, when desired,

\ as fall within the scope of the following claims.

We claim: 1. In combination with a printing machine, a feed table fixedly related to the machine and adapted to support a stack of sheets for their successive feeding to the machine while the stack bottom remains at a constant level, a'friction drag shoe for reciprocation over the stack, means to resiliently engage the shoe with the top sheet on the stack during a forward working stroke thereof, means to disenga e the shoe from the stack of sheets during a return stroke thereof, and

means automatically operative to reciprocate the shoe in synchronisrn with the printingoperations of the machine.

2. A structure in accordance with claim i having the shoe and its operating means supported on the frame of the machine independently of the support of the feed table. r 3. In a paper feed, a fixed table for supporting a supply stack of sheets, a rock frame for oscillation about an axis parallel to the table bottom and perpendicular tothe path of advancement of sheets from the table, a support member mounted on the frame for rotation about an axis parallel to the frame axisand above the stack, a drag shoe for reciprocation over the stack, means mounting said shoe on said support member in fixed relation thereto and in spaced relation from the axis of rotation of the member, means to oscillate the frame for effecting working and return strokes of the shoe, and

. a fixed feed table adapted to support a stack means operative to lower the shoe upon the top sheet of the stack during each working stroke thereof and to dispose the shoe out of contact with the stack during itsretum stroke.

position for their successive, feeding from the top of the stack, a friction drag shoe for operative engagement with uccessive sheets of the stack to advance them against a fixed stop, a rock frame'carrying said shoe for effecting working and retums'trokes thereof, and means operative to effect like working strokes of the shoe for successive sheets of the stack at, their different levels.

7. In a sheet feed for a printing machine, a

table providing a tray for a supply stack of sheets and fixedly related to the machine, a rock operative from 'the machine mechanism and through the support member to oscillatethe frame for effecting working and return strokes of the shoe, and means operative from the machine mechanism and directly upon the support member to lower the shoe upon the top sheet of the stack during .each working stroke thereof and to dispose the shoe out of contact with thestack during its return strokes.

8. In combination with a printing machine,

of sheets for their successive feeding to the machine, a friction drag shoe for reciprocation over'the stack, means to resiliently engage the shoe with the top sheet on the stack with a progressively decreasing pressure during each forward stroke thereof, means to disengage the shoe from the stack of sheets during each return stroke thereof, and means wholly in advance of of the shoe automatically operative to reciprocate the shoe in synchronism with the printing operations of the machine.

9. A structurev in accordance with claim 7 wherein the last means comprises amovable 

